In a hospital accommodating patients, an in-hospital informing system using medical equipment generating a nurse call or an alarm is used as a system for informing a medical worker of a patient requiring emergency treatment (JP-A-2013-208253 (Patent Literature 1).
However, for example, a patient who may fall from a bed in a REM sleep state does not require emergency treatment but should be watched with care.
In order to watch the patient who may fall from the bed, it is effective to watch the patient so as to correspond to a sleep state by specifying whether the sleep state of the patient is REM sleep or Non-REM sleep. Here, the specification of the sleep state can be determined by an electroencephalograph using multi-channel electrodes and by measuring brain waves using a paste for reducing noise.
However, the electroencephalograph using multi-channel electrodes or the electroencephalograph using the paste for reducing noise is a heavy burden for the patient, and the measurement is also a heavy burden for the medical worker performing measurement.